Electric heaters



1965 c. F. KREISER 3,202,795

ELECTRIC HEATERS Filed 001;. 13, 1961 E 201% EL -z W UNI A z if y INVENTOR. Eegkl wflzd/ GARLF. KRElfiER 14 54 Arramm/ United States Patent 3,202,795 ELECTRIC HEATERS Carl F. Kreiser, Export, Pa, assignor to Edwin L. Wieganrl, Pittsburgh, Pa. Filed Oct. 13, 1961, Ser. No. 144,889 6 Claims. (Cl. 219-318) My invention relates to electric immersion heaters and the principal object of my invention is to provide new and improved heaters of the character described.

sion heater applied to a tank wall mounting of a particular type, parts being shown in elevation,

FIGURE 2 is a section generally corresponding to the line 22 of FIGURE 1,

FIGURE 3 is a perspective view of an adapter of my invention,

FIGURE 4 is a perspective view of a different type of tank wall mounting,

FIGURE 5 is a sectional view generally similar to FIGURE 1, but showing employment of my invention in adapting the heater of FIGURE 1 to the tank wall mounting of FIGURE 4, and

FIGURE 6 is a sectional view showing employment of my invention in adapting the heater of FIGURE 1 to a still different type of tank wall mounting.

The heater herein disclosed is similar to the heater disclosed in the pending application of Lester D. Drugmand, Serial No. 118,980, filed June 22, 1961, entitled, Electric Immersion Heater Assembly (now Patent 3,134,- 889), and assigned to the assignee of this invention.

Briefly, such heater comprises a head 10, and a sheathed heater portion 11 shown as of the hairpin type. The heater head may be any suitable enlargement at the outer end of the heater sheath, such as a plug, but preferably as a flat rectangular relatively thick flange 12 formed of a metal which is inexpensive, such as a steel stamping, but which is subject to corrosive action when contacted by the contents of the tank T.

In accordance with the Drugmand disclosure, a flat gasket 14 overlies thatside of the head or flange which is directed toward the wall 15 of the tank T and headed bushings 9 secure the gasket 14 and the legs of the sheath portion 11 to the head or flange 10 in rigid, fluid-tight relation. The gasket may be made of any suitable sealing material, and preferably is made of a relatively hard gasket material,

such as, for example, a compressed composition of natural or synthetic rubber and asbestos and protects the steel flange from contact with the contents of the tank T. A dielectric terminal block 16 overlies and is held against the opposite side of the flange 12 and supports connection members 17-17 which are electrically connected to the oposite terminals of the resistance wire (not shown) which is disposed within the sheathed heater portion 11.

The tank wall mounting 18 shown in FIGURES l and 2 is of a type commonly used for connecting an immersion heater to the tank wall 15, and is usually made as a steel forging having a cylindrical portion 19 and a rectangular flat flange-like portion 20 generally of the same size and shape as the flange 12 of the heater. The free end of the cylindrical portion 19 is welded to the tank wall in fluid-tight position surrounding the tank opening 21. The opposite end of the mounting 18 is formed with a circular, flat gasket surface 22, and means are provided to press the gasket 14 against the gasket surface 22 to prevent leakage of the contents of the tank at this place. The heater head 10 and the mounting 18 may have screw-threaded 3,202,795 Patented Aug. 24, 1965 connection, in the event the head is formed as a plug or cap, but in the case of the flat flange 12 bolts 23 pass through aligned holes in the flange 12 and slots in the flange-like portion 20, preferably at four corners as shown in FIGURE 2. The heads 24 of the bolts bear against the outer surface of the flange 12 and the bolt shanks are tzhreaded into nuts at the rear of the flange-like portion More recently, other and less expensive tank wall mountings have been used in securing an immersion heater to a tank wall, and the gasketed construction of the heater shown in FIGURE 1 was not heretofore suitable for use with such other mountings. This required the manufacturer to make different types of heaters and the supplier to stock such types, all with an increase in cost to the final purchaser. Now,- however, my invention makes it possible to use the immersion heater shown in FIGURE 1 with other types of wall mountings, such as for example the wall mountings shown in FIGURES 4 and 5 and in FIGURE 6.

The wall mounting 25 in FIGURES 4 and 5 is preferably a steel stamping to reduce production cost. As best seen in FIGURE 4, the mouting has a fiat base portion 26 from which are struck upwardly extending pockets 27 (four shown in the present illustration). The pockets are slotted to pass the shanks of fastening bolts 28, the nuts 29 fitting the bolts being adapted to snugly fit within respective pockets to hold the nuts against rotation, and the bolt heads 30 bear against the outer surface of the flange 12. It is again pointed out that any other suitable means may be used to draw the head of the heater toward the tank wall, particularly when the head is formed other than as a flange.

The base portion 26 of the wall mounting 25 is spot welded or otherwise rigidly secured to the exterior of the tank wall 15, the opening 31 in the base portion being of greater diameter than the opening 21 in the tank wall and is arranged concentric with the latter opening to provide an annular lip 32. The tank wall may be flattened in the area of the lip 32 although with large diameter tanks this may not be necessary.

A ring-like gasket or grommet 33 of neoprene, or other suitable material which is resistant to deleterious action of the tank contents, is disposed to overlie the lip 32. In lined tanks, the lining may not be as protective as it should be in the vicinity of the tank wall opening 21 and it has holding the gasket in predetermined position in the tank opening.

An adapter member 34, best seen in FIGURE 3, is provided to adapt the heater for use with the wall mounting 25. The adapter is tubular or sleeve-like in form and is preferably made of a rigid material, such as brass, which is resistant to the corrosive action of the tank contents. The adapter has opposed end surfaces 35, 36 adapted to be disposed between the flat gasket 14 and the gasket 33, the cylindrical wall 37 of the adapter being of a length to slightly space the gasket 14 from the adjoining surfaces of the pockets 27, as seen in FIGURE 5. When the nuts 29 are tightened on the bolts 28, the flange 12 is drawn toward the tank wall 15. The edge 35 of the adapter 34 is relatively narrow so that it is readily pressed into the gasket 14 to effect a fluid-tight seal.

The pressing action of the flange 12 (caused by drawing the nuts 29 up on the bolts 28) urges the adapter 34 in a direction toward the tank wall and thus compresses the gasket 33 between the edge 36 and the lip 32 to effect a fluid-tight seal. The edge 36 is relatively wide to present a considerable flat area against the gasket 33 and thus prevent curling or other serious distortion of the gasket which otherwise might affect the seal.

In FIGURE 6, another type of wall mounting 38 is shown, this mounting comprising a relatively thick steel stamping which is rectangular and of a general size corresponding to the size of the flange 20 hereinbefore described. The mounting 38 is welded to the tank wall 15 so that its circular opening 39 circumscribes the tank opening 21 and forms a lip 32a. The mounting 38 is provided with four threaded holes 40 to respectively receive bolts 41 which pass through corresponding holes in the heater flange 12. The adapter 34, as before, is disposed between gasket 14 and gasket 33a and affects the seal as before.

In view of the foregoing, it will be apparent to those skilled in the art that I have accomplished at least the principal object of my invention and it will also be apparent to those skilled in the art that the embodiment herein described may be variously changed and modified, without departing'from the spirit of the invention, and that the invention is capable of uses and has advantages not herein specifically described; hence it will be appreciated that the herein disclosed embodiment is illustrative only, and that my invention is not limited thereto.

I claim: I Y

1. The combination of a hot water tank and an electric immersion heater for heating the contents of said tank, said tank having an opening in a defining wall and a supporting flange rigidly secured to said wall and disposed exteriorly thereof, said suporting flange having an opening therethrough which is aligned with but is larger than the tank opening so as to leave exposed a lip provided by the tank wall surface margining said tank opening, and 'said heater including a sheathed electric heating element extending through said tank opening and into said tank and a mounting flange secured to said sheath and extending crosswise thereof, said mounting flange overlying lip and spaced axially outwardly from the latter, a rigid annular member around said sheath and having opposed end surfaces respectively adjoining said lip andsaid mounting flange portion, a first sealing gasket secured to said lip and lying between said lip and the adjoining end surface of said annular member and a second sealing gasket :secured to said mounting flange and lying between said mounting flange portion and the adjoining opposite end surface of said annular member, and means drawing said mounting flange toward said supporting flange to compress said first gasket between said lip and the adjoining .end surface of said annular member and to compress said second gasket between said supporting flange and the opposite end surface of said annular member to seal the .opening in said tank wall against leakage ofwater.

2. The construction of claim 1 wherein said first sealing surface of said annular member.

said supporting flange and having a portion overlying said 3. The construction of claim 1 wherein said second sealing gasket overlies the entire surface of the mounting flange exposed to the contents of said tank.

4. The construction of claim 1 wherein said annular member is formed of metal which is resistant to corrosive action of the contents of said tank.

5. The construction of claim 1 wherein the surface of said mounting flange confronting said supporting member and said lip is substantially planar.

6. The combination of a hot water tank and an electric immersion heater for heating the contents of said tank, said tank having an opening in a defining wall and a supporting flange rigidly secured to said wall and disposed exteriorly thereof, said supporting flange having an opening therethrough which is aligned with but is larger than the tank opening so as to leave exposed a lip provided by the tank wall surface margining said tank opening, and said heater including a sheathed electric heating element extending though-said tank opening and into said tank and a mounting flange securedto said sheath and having a flat portion overlying said supporting flange and said lip and spaced laterally from the latter, a tubular member formed of metal which is resistant to corrosive action of the contents of said tank, said tubular member being disposed around said sheath and having a wide-faced end surface adjoining said lip and a narrow-faced end surface adjoining said mounting flange flat portion, a rubber grommet having a peripheral groove into which that portion of the tank wall around its opening is closely received and a wall overlying said lip and disposed between the latter and the wide-faced end surface of said tubular member, a flat sealing gasket secured to said mounting flange and overlying said flat portion to protect it from contact with the contents of said tank, said flat sealing gasket being disposed betweensaid flat portion and the narrowfaced end surface of said tubular member, and means drawing said mounting flange toward said supporting flange to cause said wide-faced end surface to compress said grommet wall between it and said tank lip and to compress said flat gasket between said narrow-faced end surface and said flat portion of said mounting flange to thereby seal the opening in said tank wall against leakage of water.

References Cited by the Examiner UNITED STATES PATENTS RICHARD M. WOOD, Primary Examiner. ANTHONY BARTIS, Examiner. 

1. THE COMBINATION OF A HOT WATER TANK AND AN ELECTRIC IMMERSION HEAATER FOR HEATING THE CONTENTS OF SAID TANK, SAID TANK HAVING AN OPENING IN A DEFINING WALL AND A SUPPORTING FLANGE RIGIDLY SECURED TO SAID WALL AND DISPOSED EXTERIORLY THEREOF, SAID SUPPORTING FLANGE HAVING AN OPENING THERETHROUGH WHICH IS ALIGNED WITH BUT IS LARGER THAN THE TANK OPENING SO AS TO LEAVE EXPOSED A LIP PROVIDED BY THE TANK WALL SURFACE MARGINING SAID TANK OPENING, AND SAID HEATER INCLUDING A SHEATHED ELECTRIC HEATING ELEMENT EXTENDING THROUGH SAID TANK OPTNING AND INTO SAID TANK AND A MOUNTING FLANGE SECURED TO SAID SHEATH AND EXTENDING CROSSWISE THEREOF, SAID MOUNTING FLANGE OVERLYING SAID SUPPORTING FLANGE AND HAVING A PORTION OVERLYING SAID LIP AND SPACED AXIALLY OUTWARDLY FROM THELATTER, A RIGID ANNULAR MEMBER AROUND SAID SHEATH AND HAVING OPPOSED END SURFACES RESPECTIVELY ADJOINING SAID LIP AND SAID MOUNTING FLANGE PORTION, A FIRST SEALING GASKET SECURED TO SAID LIP AND LYING BETWEEN SAID LIP AND THE ADJOINING END SURFACE OF SAID ANNULAR MEMBR AND A SECOND SEALING GASKET SECURED TO SAID MOUNTING FLANGE AND LYING BETWEEN SAID MOUNTING FLANGE PORTION AND THE ADJOINING OPPOSITE END SURFACE OF SAID ANNULAR MEMBER, AND MEANS DRAWING SAID MOUNTING FLANGE TOWARD SAID SUPPORTING FLANGE TO COMPRESS SAID FIRST GASKET BETWEEN SAID LIP AND THE ADJOINING END SURFACE OF SAID ANNULAR MEMBER AND TO COMPRESS SAID SECOND GASKET BETWEEN SAID SUPPORTING FLANGE AND THE OPPOSITE END SURFACE OF SAID ANNULAR MEMBER TO SEAL THE OPENING IN SAID TANK WALL AGAINST LEAKAGE OF WATER. 